DE 10 2010 035 465 A1 discloses a filter for filtering fluids, in particular liquid fluids, in particular fuel or oil, in particular of an internal combustion engine, the filter comprising a filter pot in which a filter element is arranged, and a filter head having an inlet and/or an outlet for the fluid. The filter head and the filter pot are connected to one another by means of a releasable bayonet-type rotational/plug-in connector. The rotational/plug-in connector comprises at least two interacting catch components, one of which is connected to the filter pot and the other of which is connected to the filter head.
The invention addresses the problem of providing a treatment device and a replaceable filter of a filter device of the aforementioned type, with which it is possible to facilitate the connection of the treatment element, in particular of the replaceable filter to the connecting head and facilitate separation from the connecting head. The invention is also intended to reduce the space required, in particular for the connecting device, in particular in the axial direction with respect to the connecting axis.